Compression packer

ABSTRACT

The invention is a compression (set down) packer with a slip type hold down actuated by hydraulic pressure from below the packing elements. The packer is full opening and will permit through-tubing operations. Once the packer&#39;&#39;s downward movement is stopped and the packer elements expanded by conventional means including J-slot pin means for preventing unwanted expanding of the lower slips, pressure from below the packer (applied through the tubing to which the packer is attached) forces a piston and, usually, at least one booster piston upwardly to move a slip cone under the tapered surface of the upper slips to cause them to bear against the wall surface, usually the casing of the well. This outward movement of the slips stops upward movement of the packer device. Because a vacuum is created when the piston advances under pressure, once hydraulic pressure is released (or greatly reduced), the piston and slip cone retracts to relieve the vacuum condition. Subsequently, placing tension on the tubing releases the lower slips and the packer may be withdrawn from the well.

United States Patent 1 Pitts [451 Nov. 5, 1974 COMPRESSION PACKER [75]Inventor: Charles A. Pitts, Wichita Falls, Tex.

[73] Assignee: The Dow Chemical Company,

Midland, Mich.

221 Filed: July 23,1973

21 Appl. No.: 381,647

[52] US. Cl. 166/120, 166/134 [51] Int. Cl E21b 23/06 [58] Field ofSearch 166/120, 134

[56] References Cited UNITED STATES PATENTS 3,094,169 6/1963 Conrad166/134 3,399,729 .9/1968 McGill 1 t 166/120 3,426,846 2/1969 Young166/120 X 3,586,106 6/1971 Conrad 166/120 2/1972 McGill .1 166/120Primary ExaminerDavid H. Brown Attorney, Agent, or Firm-Earl D. Ayers[57] ABSTRACT The invention is a compression (set down) packer with aslip type hold down actuated by hydraulic pressure from below thepacking elements. The packer is full opening and will permitthrough-tubing operations.

Once the packers downward movement is stopped and the packer elementsexpanded by conventional means including J-slot pin means for preventingunwanted expanding of the lower slips, pressure from below the packer(applied through the tubing to which the packer is attached) forces apiston and, usually, at least one booster piston upwardly to move a slipcone under the tapered surface of the upper slips to cause them to bearagainst the wall surface, usually the casing of the well. This outwardmovement of the slips stops upward movement of the packer device.

Because a vacuum is created when the piston advances under pressure,once hydraulic pressure is released (or greatly reduced), the piston andslip cone retracts to relieve the vacuum condition.

Subsequently, placing tension on the tubing releases the lower slips andthe packer may be withdrawn from the well.

5 Claims, 2 Drawing Figures Pmmmuuv 5 m4 SHEET 1 (I? 2 l COMPRESSIONPACKER BACKGROUND OF THE INVENTION OBJECTS OF THE INVENTION pressionpacker assembly.

STATEMENT OF INVENTION In accordance with this invention, there isprovided a compression packer apparatus comprising an elongated tubularinner mandrel joined at one end to an upper connector member and at theother end to a lower connection member.

Outside the mandrel at the lower part of the apparatus isa lower slipassembly of known design operated by relative movement between the dragblock part of the assembly and the mandrel, the mandrel controlling themovement of the lower slip cone which controls expansion of the slips. Asleeve-like member coupled to the lower slip cage has a J-slot in itinto which a boss on the lower connection extends. Thus, until rotationof the mandrel (and thus rotationof the boss to put it in the long partof the .l-slot occurs, there is no relative movement between the lowerslip cone and the slips.

As the mandrel is lowered to move the lower slip cone downwardly, thepacking elements, disposed just above the slip cone and around aslidable sleeve, are expanded to seal against the well bore wall,usually the well casing.

An upper slip assembly is fixedly coupled to the upper connector memberaround the mandrel and is surrounded by a cage sleeve which extendsdown-.

wardly past the slip elements of the assembly.

Above the packer seal elements and below the slip elements of the upperslip assembly is disposed an upper slip cone and its hydraulic actuatingmeans. The actuating means is a booster piston and a drive pistoncoupled to the slip cone and disposed between the outer surface of themandrel and the inner cover of the slip assembly cage and the attachedhold down coupling and booster housing below the'slip assembly.

A fluid input port just above the lower slip cone permits pressurizedfluid from below the packer to enter and travel upwardly between themandrel and packing sleeve and beyond to actuate the booster piston andhold down piston.

As the hold down piston advances, a vacuum is created in the space oneside of the piston and the adjacent wall structure. This vacuumfacilitates later releasing of the slips.

BRIEF DESCRIPTION OF THE DRAWINGS The invention, as well as additionalobjects and advantages thereof, will best be understood when thefollowing detailed description is read in connection with theaccompanying drawings, in which:

FIG. 1 is a segmented side elevational view, partly broken away and insection, of apparatus in accordance with this invention, and

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1..

DETAILED DESCRIPTION OF THE DRAWINGS Referring to the drawing, there isshown compression packer apparatus, indicated generally by the numeral10, including an elongated tubular inner mandrel 12 having externallythreaded ends coupled to an upper connector 14 and a lower connector 16,respectively. The upper connector 14 is a tubular element havinginternal threads at eaCh end, the lower end being coupled to the mandrel12 and the upper end for coupling to a tubing string, for example.

There is an outwardly extending shoulder intermediate theends of theconnector 14, the outer surface adjacent to the shoulder being threaded.An upper cage ring is coupled to the threads adjacent to the upper sideof the shoulder.

A cage sleeve having cutouts through which slip elements 86 protrude iscoupled at its upper end to the lower external threads of theconnec'torl4. The lower end of the cage sleeve 70 is threadedly coupledto a hold down coupling 66.

An array of slip elements 86 each attached to a leaf spring 88 andsupported from a ring-like block 90 disposed contiguous to the lower endof the upper connector l4.

The lower connector 16 is an elongated tubular member having externalthreads 98 at its lower end and a smooth cylindrical outer wall surfacefrom adjacent to the threads 98 to the upper end of the member. A stud24 extends outwardly from the upper end part of the connector 16.

A sleeve 26 containing a .l-shaped slot 100 therein fits closely butslidably around the lower connector and extending above the connector16, being threadedly coupled at its upper end to the outer lower part ofthe lower slip cage 30 and thus to the drag blocks 32.

The outer periphery of the sleeve 26 is covered at least over the lengthof the J-slot 100 by the sleeve 28.

The drag blocks 32 extend through slots in a tubular sleeve 34 whichfits over part of the outer surface of the lower slip cage 30.

The slip elements 36 are supported from the drag block members generallyas shown in US. Pat. No. 3,710,866 or in U.S. Pat. No. 3,705,624 andextend upwardly beyond the sleeve 34 adjacent to the exterior of themandrel l2.

The lower slip cone element 38 is disposed around the mandrel 12 abovethe slip elements 36. The cone element 38 is sleeve-like with internalthreads at its upper end and a tapered conical end part at its lowerend.

The element 38 iscounter-bored from its upper end to a point adjacent tothe conical lower end. A fluid entry port 102 extends through the wallof the lower slip cone near the conical end, communicating with thecounterbored part.

The internally threaded upper end of the cone element 38 is coupled toexternal threads at the lower end of a lower sleeve element 40 whoseinner wall is of smaller diameter than the inner diameter of thecounterbored part of the lower slip cone element.

A lower packing guide rim 44 of generally L-shaped transversecross-sectional configuration surrounds the upper end of the lowersleeve element 40, presenting a flat surface perpendicular to thelongitudinal axis of the mandrel 12.

One end of the rim bears against the upper end of the lower slip coneand the other end bears against the mandrel 12 with the adjacent sidebearing against the upper end of the lower sleeve 40.

An array of packer ring elements 46 separated by metal spacer rings 48are disposed over the mandrel l2 and extend between the lower packingguide rim 44 and an upper packing guide rim 50 which is similar in sizeand configuration to the guide rim 44.

The upper packing guide rim 50 at its lower end and its side bearsagainst the lower end and outer side of the packer connection member 52which is a sleeve-like member surrounding and spaced from the mandrel l2and has an outwardly extending shoulder intermediate of its ends. Theinner peripheral surface below the shoulder is threaded, as is the outerperipheral surface above the shoulder.

An elongated packing sleeve 42 has its upper end engaging with the innerperipheral threads of the packer connection 52 and is sealed withrespect thereto by means of the O-ring seal 54 in the inner peripheralwall of connector 52.

The lower sleeve 40, lower packing guide rim 44, packer elements 46,spacer elements 48, and the upper guide rim 50 each fit slidably overthe outer peripheral surface of the packing sleeve 42 which in turn isspaced from and fits over the outer periphery of the mandrel 12.

The lower end of the packing sleeve 42 has an outwardly extendingshoulder which extends into the counterbored part of the lower slip cone38. The diameter of the shoulder part exceeds the inner diameter of thelower sleeve 40.

A booster housing sleeve 58 is threadedly coupled to the upper threadsof the packer connection member 52 and at its upper end to the lowerexternal threads of the hold down coupling 66. A pressure relief port 64is provided in the booster housing wall just below the hold downcoupling 66.

An O-ring seal 56 is provided in the outer periphery of the upper partof the packer connection member 52 to provide a seal between the member52 and the booster housing sleeve 58.

As mentioned previously, the parts between the booster housing and thelower slip cone surround the mandrel 12 and are spaced from it toprovide a fluid passage from the port 102 to the booster housing sleeve58.

The inner wall of the booster housing sleeve is smooth and of constantdiameter, defining the inner cylinder wall in which the booster piston60 is disposed.

The booster piston 60 is a sleeve-like member having an outwardlyextending shoulder part at its lower end. An O-ring seal 62 is providedbetween the booster piston shoulder and the inner wall of the boosterhousing 58.

The upper end part of the booster piston 60 extends above the lower endof the hold down coupling 66. An O-ring seal 68 is provided between theshoulder and inner wall of the hold down coupling 66.

The hold down piston 72 lies between the outer surface of the mandrel l2and the inner surface of the cage 70 and hold down coupling 66, with itslower end touching or adjacent to the upper end of the booster piston60.

The hold down piston 72 is an elongated tubular element having a sectionof reduced outer diameter near its lower end where it fits slidably overthe inner surface of the upper part of the hold down coupling 66. O-ringseals 74, 78 are provided between the outer surface of the hold downpiston and the inner surface of the hold down coupling and the innersurface of the cage member 70, respectively.

The upper end of the hold down piston is coupled, by pin 84, to thelower end of the upper slip cone 80 which fits slidably between themandrel 12 and cage 70. An O-ring wiper 82 is provided between thenon-tapered outer surface of the upper slip cone 80 and the inner wallof the cage 70.

The upper end of the cone 80 is tapered to fit under, and on upwardmovement, force outwardly the upper slip elements 86.

An O-ring seal 104 is also provided between the hold down piston 72 andthe outer wall of the mandrel 12 adjacent to the upper end of the piston72.

OPERATION In operation, the apparatus 10 is usually lowered into a casedbore hole to a desired depth at or near the end of a string of tubing.

The drag block elements 32 provide considerable frictional contact withthe casing wall (not shown). When the apparatus is in position in thecasing, the tubing is rotated to place the boss or pin 24 in line withthe long part of the .l-slot 26 and the tubing is then lowered, carryingthe mandrel l2 and entire assembly down to the lower slip cone 38downwardly. The lower slip cone 38 advances under the lower slipelements 36, forcing slip elements 36 outwardly to bite into the casingand prevent further downward movement of the apparatus.

As the mandrel 12 is moved downwardly to set the slip elements 36, thepacking elements 46 are compressed and expanded to seal the annulusbetween the casing and the apparatus 10, the packing sleeve slidingdownwardly as the elements 46 are compressed.

Once the packer elements seal the above-mentioned annular space, fluidis pumped through the tubing and mandrel 12 into the casing below theapparatus 10.

The pressurized fluid enters through the fluid input port 102 in thelower slip cone and rises in the space between the mandrel and thepacking sleeve 42, packer connection 52, booster housing 58 and part ofthe hold down coupling 66 to put pressure on the booster piston 60 andhold down piston 72 to move the upper cone sleeve upwardly underneaththe upper slip elements 86, forcing the slip elements 86 against thewall of the easing to prevent upward movement of the casing.

As the hold down piston 72 moves upwardly, a vacuum is created in thespace left as the shoulder 106 of the hold down piston moves away fromthe upper end of the hold down coupling 66. Seals 74 and 78 assure thatvacuum conditions are maintained in the space.

After the pressurized treatment of the well bore is completed, pressureis relieved on the tubing and the loss of pressure plus the vacuumcreated as the hold down piston advances results in the upper slip conebeing retracted. The springs 88 then force the slip elements 86inwardly.

The apparatus then may be moved upwardly by upward movement of thetubing, drawing the lower slip cone 38 upwardly and removing thecompression of the packer elements 46.

If the apparatus is to be lowered into the casing (or to be moved ineither direction, if wanted), the tub ing is rotated while under tensionto place the boss or pin 24 in the rest position of the .l-slot 26 toprevent relative movement between the drag block elements 32 and thelower slip cone 38.

The total top area of the piston 72 exceeds the total area of the lowerpiston parts. Therefore, the well bore pressure and vacuum cause thereturn of the piston 72 to the at reat position, retracting the upperslip cone 80.

I claim: 7

1. Compression packer apparatus comprising an elongated tubular innermandrel having upper connector means at one end and lower connectormeans at the lower end thereof, a slip element and compression packerelement assembly including packer elements, drag blocks and a lower slipcone carried around the lower part of said mandrel assembly, means formechanically compressing said packer elements and for advancing saidlower slip cone under said slip elements, an upper slip array having atapered under side disposed above said packer elements and surroundingsaid mandrel, a slidable upper slip cone disposed around said mandreladjacent to said tapered underside of said slip array, hydraulic pistondrive means coupled to said 7 upper slip cone and disposed around saidmandrel, channel means for applying pressurized fluid from below saidpacker elements to said piston drive means, and vacuum actuated upperslip cone retraction means coupled to said piston drive means.

2. Apparatus in accordance with claim 1, wherein said hydraulic pistondrive means includes an actuating piston and at least one boosterpiston, said pistons being disposed in end-to-end relationship.

3. Apparatus in accordance with claim 1, wherein sald means formechanically compressing said packer elements includes at least onepiston fitting closely between the outer surface'of said mandrel and anouter housing sleeve assembly. 7

4. Apparatus in accordance with claim 3, wherein the outer housingsleeve assembly has a reduced inner diameter part and said piston has anormal diameter part and has a reduced outer diameter part substantiallycoextensive in length with said reduced inner diameter part, saidreduced inner and outer diameter parts telescoping closely but slidablywith respect to each other, and spaced apart seal means between saidpiston and said outer housing sleeve for restricting fluid flow betweensaid piston and said outer housing assembly whereby as said pistonadvances, a vacuum is created in the space between the parts of saidpiston and housing assembly having differing diameters.

5. Apparatus in accordance with claim 3, wherein said piston has a largediameter forward part and a reduced diameter rear part. and said housingassembly has a larger inner diameter forward part and a reduced outerdiameter rear part, said parts being telescoped to a maximum extent whensaid upper slip cone is ret'racted and said differing diameter partsdefining an open space when said upper slip cone is in its advancedposition as a result of upward motion of said piston.

1. Compression packer apparatus comprising an elongated tubular innermandrel having upper connector means at one end and lower connectormeans at the lower end thereof, a slip element and compression packerelement assembly including packer elements, drag blocks and a lower slipcone carried around the lower part of said mandrel assembly, means formechanically compressing said packer elements and for advancing saidlower slip cone under said slip elements, an upper slip array having atapered under side disposed above said packer elements and surroundingsaid mandrel, a slidable upper slip cone disposed around said mandreladjacent to said tapered underside of said slip array, hydraulic pistondrive means coupled to said upper slip cone and disposed around Saidmandrel, channel means for applying pressurized fluid from below saidpacker elements to said piston drive means, and vacuum actuated upperslip cone retraction means coupled to said piston drive means. 2.Apparatus in accordance with claim 1, wherein said hydraulic pistondrive means includes an actuating piston and at least one boosterpiston, said pistons being disposed in end-to-end relationship. 3.Apparatus in accordance with claim 1, wherein saId means formechanically compressing said packer elements includes at least onepiston fitting closely between the outer surface of said mandrel and anouter housing sleeve assembly.
 4. Apparatus in accordance with claim 3,wherein the outer housing sleeve assembly has a reduced inner diameterpart and said piston has a normal diameter part and has a reduced outerdiameter part substantially coextensive in length with said reducedinner diameter part, said reduced inner and outer diameter partstelescoping closely but slidably with respect to each other, and spacedapart seal means between said piston and said outer housing sleeve forrestricting fluid flow between said piston and said outer housingassembly whereby as said piston advances, a vacuum is created in thespace between the parts of said piston and housing assembly havingdiffering diameters.
 5. Apparatus in accordance with claim 3, whereinsaid piston has a large diameter forward part and a reduced diameterrear part and said housing assembly has a larger inner diameter forwardpart and a reduced outer diameter rear part, said parts being telescopedto a maximum extent when said upper slip cone is retracted and saiddiffering diameter parts defining an open space when said upper slipcone is in its advanced position as a result of upward motion of saidpiston.